Testosterone production declines with age. Testosterone deficiency (TD) may result from disease or damage to the hypothalamus or pituitary gland, or from the testicles themselves. This condition is known as hypogonadism. Depending on age, insufficient testosterone production can lead to abnormalities in muscle and bone development, underdeveloped genitalia, and diminished virility.

The testes produce testosterone regulated by a complex chain of signals that begins in the brain. This chain is called the hypothalamic-pituitary-gonadal axis. The hypothalamus secretes gonadotropin-releasing hormone (GnRH) to the pituitary gland in carefully timed pulses (bursts), which triggers the secretion of leutenizing hormone (LH) from the pituitary gland. Leutenizing hormone stimulates the Leydig cells of the testes to produce testosterone. Normally, the testes produce 4–7 milligrams (mg) of testosterone daily.

State of the art diagnostic tools and treatments for Testosterone Deficiency

TREATMENT

Treatment involves hormone replacement therapy. The method of delivery is determined by age and duration of deficiency.

Treatment for adults is aimed at maintaining secondary sex characteristics, improving energy, strength, mood, and feelings of well-being, and preventing bone degeneration. Modes of delivery include transdermal or intramuscular injection.

TRANSDERMAL DELIVERYTransdermal delivery (through the skin) with a testosterone patch or gel is becoming the most common method of treatment for testosterone deficiency in adults. It establishes and maintains adequate serum levels in as many as 92% of men treated, without causing significant side effects.

INTRAMUSCULAR INJECTION (IM)Intramuscular injection (IM) is used less frequently because it is associated with erratic testosterone levels. The primary adverse effect associated with injected testosterone involves fluctuating mood, energy level, and libido caused by testosterone levels that rise rapidly upon injection and then fall too low before the next dose.

TESTOPEL®
One of the long-term treatment options is the insertion of subcutaneous pellets called Testopel®. This is done with a short 3 minute procedure in the office every 4 months for most patients.